Instant runoff voting was introduced in Aspen in last May’s municipal election. This November, in an informal advisory question, the city wants to know if voters liked the new method or not.

If voters say they don’t like IRV, the city might move to scrap IRV and go back to the previous runoff system. This would require another vote in the form of a formal charter amendment.

If voters express confidence in IRV, the city will likely move to tweak the way the system works.

IRV allows voters to rank their candidate preference. If no candidate receives a majority vote after voters’ first choices are counted, then lower-ranking candidates are eliminated with those voters’ votes going to their next preference. The system repeats itself until someone ends up with a majority. Proponents of IRV point out that the system saves the time and expanses of a runoff election. Those opposed to the system say it has the capacity for mathematical anomalies and deprives the community of the chance to get to know leading candidates better.

Various members of City Council have sought to implement IRV in Aspen at least since 2005 when former Councilman Jack Johnson pushed for the system. After the May 2007 election, when the runoff election held one month after the initial vote confirmed the preference expressed in that initial vote — as had happened every time since the city began holding runoff elections in 2001 — council put a charter amendment on the November 2007 ballot to implement IRV. Voters approved the question by a 76 percent margin.

It wasn’t until weeks before last May’s election that the city settled on the IRV method for Aspen’s council races, where any number of candidates compete for two open seats. The method implemented counts voters’ first two choices equally, and then runs a sequential elimination until two candidates have a majority.

In the run up to and since the election, IRV has been a source of controversy. Three weeks after the vote, the city disclosed that a software error had led to the miscounting of 28 votes (the error did not change the outcome of the election). Marilyn Marks, who came in second in IRV voting for the mayor’s race, has sued the city to release the ballot images from the election, which would be used to cross-check city records in the course of an independent election review.